Bar code scanner having a mirrored spinner which operates at different speeds

Abstract

A bar code scanner has a housing including a surface having a transparent scanning window. The housing contains optical components including a spinner and pattern mirrors arranged to produce sets of scan lines. The spinner is operable at two, substantially constant, non-zero spin speeds.

1. A bar code scanner comprising:
 a mirrored spinner for directing a laser beam towards a plurality of stationary pattern mirrors and for directing received light; 
 a motor for rotating the mirrored spinner; 
 a detector for converting the received light into electrical signals; 
 decoding circuitry for decoding bar code information from the electrical signals; and 
 control circuitry for switching operation of the motor between a first non-zero speed and a second non-zero speed about half the first non-zero speed based upon amounts of the bar code information received in predetermined periods of time; 
 wherein the first non-zero speed is about 8,000 rpm to 10,000 rpm, and wherein the second non-zero speed is about 4,000 rpm to 5,000 rpm. 
 
   
   
     2. The bar code scanner of  claim 1 , wherein the control circuitry switches from the first non-zero speed to the second non-zero speed if the control circuitry has not detected the bar code information for a first predetermined period of time. 
   
   
     3. The bar code scanner of  claim 2 , wherein the first predetermined time comprises about 5 minutes. 
   
   
     4. The bar code scanner of  claim 3 , wherein the control circuitry turns off the motor if the control circuitry has not detected the bar code information for a second predetermined period of time. 
   
   
     5. The bar code scanner of  claim 2 , wherein the control circuitry switches from the second non-zero speed to the first non-zero speed if the control circuitry has detected bar code information for more than a second predetermined time period. 
   
   
     6. The bar code scanner of  claim 5 , wherein said second predetermined time period comprises 30 seconds. 
   
   
     7. The bar code scanner of  claim 1 , wherein the mirrored spinner comprises a plurality of mirrored facets, each of the facets being mounted at a different angle to an axis of rotation of the motor. 
   
   
     8. A scanning method comprising:
 a) directing a laser beam towards a plurality of stationary pattern mirrors and directing received light from the stationary pattern mirrors; 
 b) rotating the mirrored spinner by a motor; 
 c) converting the received light into electrical signals by a detector; 
 d) decoding bar code information from the electrical signals by decoding circuitry; and 
 e) switching operation of the motor between a first non-zero speed and a second non-zero speed about half the first non-zero speed based upon amounts of the bar code information received in predetermined periods of time by control circuitry; 
 wherein the first non-zero speed is about 8,000 rpm to 10,000 rpm, and wherein the second non-zero speed is about 4,000 rpm to 5,000 rpm. 
 
   
   
     9. The method of  claim 8 , wherein step e) comprises:
 e-1) failing to detect the bar code information for a first predetermined period of time by the control circuitry; and 
 e-2) switching from the first non-zero speed to the second non-zero speed by the control circuitry. 
 
   
   
     10. The method of  claim 9 , wherein the first predetermined time comprises about 5 minutes. 
   
   
     11. The method of  claim 9 , wherein step e) further comprises:
 e-3) failing to detect the bar code information for a second predetermined period of time by the control circuitry; and 
 e-4) turning off the motor by the control circuitry. 
 
   
   
     12. The method of  claim 9 , wherein step e) further comprises:
 e-3) detecting the bar code information for more than a second predetermined period of time by the control circuitry; and 
 e-4) switching from the second non-zero speed to the first non-zero speed by the control circuitry. 
 
   
   
     13. The method of  claim 12 , wherein said second predetermined time period comprises 30 seconds. 
   
   
     14. A scanning method comprising:
 a) directing a laser beam towards a plurality of stationary pattern mirrors and directing received light from the stationary pattern mirrors; 
 b) rotating the mirrored spinner by a motor; 
 c) converting the received light into electrical signals by a detector; 
 d) decoding bar code information from the electrical signals by decoding circuitry; and 
 e) changing motor speed based upon amounts of the bar code information received in predetermined periods of time by control circuitry, including
 switching the motor speed from a first non-zero speed to a second non-zero speed lower than the first non-zero speed if the control circuitry has not detected the bar code information for a first predetermined period of time; 
 turning off the motor if the control circuitry has not detected the bar code information for a second predetermined period of time; 
 turning on the motor and operating it at the second non-zero speed if the control circuitry receives a signal from a motion sensor; and 
 switching from the second non-zero speed to the first non-zero speed if the control circuitry has detected bar code information for more than a third predetermined time period. 
 
 
   
   
     15. A bar code scanner comprising:
 a mirrored spinner for directing a laser beam towards a plurality of stationary pattern mirrors and for directing received light; 
 a motor for rotating the mirrored spinner; 
 a detector for converting the received light into electrical signals; 
 decoding circuitry for decoding bar code information from the electrical signals; and 
 control circuitry for switching operation of the motor between a first non-zero speed and a second non-zero speed lower than the first non-zero speed based upon amounts of the bar code information received in predetermined periods of time; 
 wherein the control circuitry switches from the first non-zero speed to the second non-zero speed if the control circuitry has not detected the bar code information for a first predetermined period of time; and 
 wherein the control circuitry switches from the second non-zero speed to the first non-zero speed if the control circuitry has detected bar code information for more than a second predetermined time period of about 30 seconds. 
 
   
   
     16. A scanning method comprising:
 a) directing a laser beam towards a plurality of stationary pattern mirrors and directing received light from the stationary pattern mirrors; 
 b) rotating the mirrored spinner by a motor; 
 c) converting the received light into electrical signals by a detector; 
 d) decoding bar code information from the electrical signals by decoding circuitry; and 
 e) switching operation of the motor between a first non-zero speed and a second non-zero speed lower than the first non-zero speed based upon amounts of the bar code information received in predetermined periods of time by control circuitry, including
 e-1) failing to detect the bar code information for a first predetermined period of time by the control circuitry; 
 e-2) switching from the first non-zero speed to the second non-zero speed by the control circuitry; 
 e-3) detecting the bar code information for more than a second predetermined period of time of about 30 seconds by the control circuitry; and 
 e-4) switching from the second non-zero speed to the first non-zero speed by the control circuitry.